Hello,

I was wondering how (or what is the best way) to write a worksheet in which a change of formula is used when a certain value on the y-axis is reached.

So for example: if there is a mass-spring system with damping in it, I would like to change the value of the damping when the displacement/velocity/acceleration has reached a certain value.
So when I apply a force to the mass-spring system, and the acceleration for example is LOWER than 0.2 m/s^2 I use a value of X % damping, but when the value of the acceleration is HIGER than 0.2 m/s^2 I want to apply Y % damping. So in time the curve will increase (when low damping is used) and the curve will decrease (because high damping is used, because the y-value is higher than 0.2 m/s^2), and so on...

I hope somebody has a 'simple' idea. I know what I want to do, but I don't know how to put this down in a formula which I can write in Maple.

Greetings,
Frank

Hi, i need help. I'm currently working with Taylor and Maclaurin series in Maple. I can easily compute the sum by typing in fx : 

taylor( (e^x,x=0, 5) , and then I get the first 5 numbers of the series. But I would like Maple to write the series as a sum from n =0 to infinity fx.  I can't figure out how to do it. Can it be done? 

Thanks for helping.

Hi,

I want to compute a formula which is too complicated and it contains some variables. So I divide it into several parts. But it always turns out kernel connection has been lost. I looked maplesoft online help system and change the ConnectionType from 0 to 2. But it does not work. So how does this happen and how to solve?

I attach my maple file which appears error.
Thanks a lot!

Regards,

Yan

Dear guys. I want to solve this equation analytically:

diff(Q(t),t)^2 = ln(t)^(b) + b*ln(t)^(b-1)

I think it is impossible. So I assumed that diff(Q(t),t)^2 = diff(P(t),t) and now I can solve it for P(t) easily. I obtained:

P(t) = t*ln(t)^(b)

Now, I want to know that there is anyway to obtain Q(t) using the latter relation and  diff(Q(t),t)^2 = diff(P(t),t) ?

Also I have a function as V(P)=P^(-2). What can I say about the behaviour of V(Q)?

Thanks a lot.

A common spreadsheet computation is to take values in column A in a spreadsheet and multiply by values in column B, e.g. A1*B1=C1; A2*B2=C2.  How do I do this in a Maple matrix?

I am trying to reduce a tensor expression: ω_iω_jU_i,j 

For which I have tried the following

Question 1. Am I using the continuity condition correctly? How do I use this condition correctly? If I change the index for the expression, substitution does not work correctly. 

Question 2. How do I expand the red_eq term in terms of the basis to give out the full expression? 

Question 3. I would like to eventually replace U by (A-Amean) in the current expression. How do I implement this? 

Download term8.mwterm8.mw

I am running into what looks like an interference between the Physics package and linear algebra, specifically when using the . (dot operator) to stand for matrix-vector multiplication:

I have a column vector and a matrix and need to evaluate the product matrix.vector. Usually this works fine and gives me the column vector with the result, just as expected. In this particular case (having with(Physics[Vectors]) at the top of the sheet) I get an error message:

Error, (in Typesetting:-delayDotProduct) invalid input: Physics:-Vectors:-`.` expects its 1st argument, a, to be of type Or({algebraic, procedure}, `=`), but received Matrix(3, 3, ...)

The Matrix it complains about is in fact the one I am sending it. It was created from a Physics:-Vectors object using the Component function (so it should be a regular Maple Matrix). In fact, the Matrix is the result of a LinearAlgebra:-MatrixInverse operation.

The weird thing is: This works when I am using 1-d input in Worksheet mode (which I am usually doing). In this case I am creating a sheet in Document mode using 2-d input as it is a sheet I will use in some teaching activity later this year, so I want it to look more polished. I can replace the dot with the relevant MatrixVectorMultiply function and it will work, but that is a kludge I don't think  should be necessary.

Anybody ever seen this? BTW, I am doing this on Maple 15 using the version of Physics that came with it.

Thanks,

Mac Dude

with(Groebner):
with(LinearAlgebra):
T := lexdeg([x1,x2,x3],[e1,e2,e3]);
hello1 := proc(xx,yy)
return MatrixMatrixMultiply(xx,yy);
end proc:
hello2 := proc(xx,yy)
return xx+yy- MatrixMatrixMultiply(xx,yy);
end proc:
m1 := Matrix(3, 3, {(1, 1) = -.737663975994461+0.*I, (1, 2) = -.588973463383001+0.*I, (1, 3) = .330094104689369+0.*I, (2, 1) = -.588012653178741+0.*I, (2, 2) = .320157823261769+0.*I, (2, 3) = -.742792089286083+0.*I, (3, 1) = -.331802619371428+0.*I, (3, 2) = .742030476217061+0.*I, (3, 3) = .582492741708719+0.*I});
m2 := Matrix(3, 3, {(1, 1) = -.742269137704830+0.*I, (1, 2) = -.590598631673326+0.*I, (1, 3) = .316590877121441+0.*I, (2, 1) = -.593533033362923+0.*I, (2, 2) = .360143915024171+0.*I, (2, 3) = -.719732518911068+0.*I, (3, 1) = -.311054762892221+0.*I, (3, 2) = .722142379823161+0.*I, (3, 3) = .617863510611693+0.*I});
m3 := Matrix(3, 3, {(1, 1) = -.751491355856820+0.*I, (1, 2) = -.574908634018322+0.*I, (1, 3) = .323636840615627+0.*I, (2, 1) = -.575794245520782+0.*I, (2, 2) = .332066412772496+0.*I, (2, 3) = -.747123071744916+0.*I, (3, 1) = -.322058579916187+0.*I, (3, 2) = .747804760642505+0.*I, (3, 3) = .580574121936877+0.*I});
AA := hello1(m1, m2);
BB := hello2(m1, m2);
GB := Basis([e1- AA,e2- BB],T):
NormalForm(m3, GB, T);

A := `<|>`(`<,>`(1, 2,3), `<,>`(2, 3, 0), `<,>`(2, 0, 0));
v, EigenVector1:= Eigenvectors(A);
FirstEigenValue := v[1];
SecondEigenValue:= v[2];
ThirdEigenValue:= v[3];
NewMatrix3 := Matrix([[x1, x2, x3],
[x2, x3,0],
[x2,0 , 0]]);
Hello :=solve([MatrixMatrixMultiply(NewMatrix3,Matrix([[EigenVector1[1][1]],[ EigenVector1[2][1]],[ EigenVector1[3][1]]]))[1][1] = FirstEigenValue* Matrix([[EigenVector1[1][1]],[ TestPredictedProj1[2][1]],[ EigenVector1[3][1]]])[1][1],
MatrixMatrixMultiply(NewMatrix3,Matrix([[EigenVector1[1][2]],[ EigenVector1[2][2]],[ EigenVector1[3][2]]]))[2][1] = SecondEigenValue* Matrix([[EigenVector1[1][2]],[ EigenVector1[2][2]],[ EigenVector1[3][2]]])[1][1],
MatrixMatrixMultiply(NewMatrix3,Matrix([[EigenVector1[1][3]],[ EigenVector1[2][3]],[ EigenVector1[3][3]]]))[3][1] = ThirdEigenValue* Matrix([[EigenVector1[1][3]],[ EigenVector1[2][3]],[ EigenVector1[3][3]]])[1][1]
], [x1,x2,x3]);

i am confused at right hand side

 FirstEigenValue* Matrix([[EigenVector1[1][1]],[ TestPredictedProj1[2][1]],[ EigenVector1[3][1]]])[1][1]

there are three values, i do not know use which value in each equation

actually, my expectation is simple, just find back the original matrix from eigenvector and eigenvalue

Hi,

plot([[F(0,0.8)(y),y,y=0..3],[F(0.1,0.8)(y),y,y=0..3],[F(0.2,0.8)(y),y,y=0..3]],numpoints=25,color=[red,green,blue],view=[-0.3..0.5,0..2.5]);

p1:=%:

data:=plottools:-getdata~([p1]):

dm1:=op([1,-1],data);

              dm1 := Vector(4, {(1) = ` 36 x 2 `*Matrix,

                        (2) = `Data Type: `*float[8], (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

dm2:=op([2,-1],data);

           dm2 := Vector(4, {(1) = ` 32 x 2 `*Matrix,

                    (2) = `Data Type: `*float[8], (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

dm3:=op([3,-1],data);

                       dm3 := Vector(4, {(1) = ` 28 x 2 `*Matrix, (2) = `Data Type: `*float[8], (3) = `Storage:                                         `*rectangular, (4) = `Order: `*Fortran_order})

How to combine these three matrices into a single one with four columns (y, F(0,0.8)(y), F(0.1,0.8)(y), F(0.2,0.8)(y) )?

Thanks

I  get  this  from  pdsolve as a  "solution"

p[42] := -Pi+.2+3.0*x+3.2*t+2*Intat(2.25*_f/sqrt(-1.5*_f*(-1.6+4.0500*_f^2+3.7125*_f)), _f = 0)

it does not eval to anything, what is this ?

Dear Maple users

My question is probably simple, but I can't seem to figure out how to do it in a smart way way without using procedures: My task is to create a cumulative list from a list. Ex: From [3,-2,5,1,10,7] I want to create the list [3,1,6,7,17,24]. Every entrance in the new list is the sum of the previous ones including the actual entrance. The Statistics package contain a command named CumulativeSum, but unfortunately a list is not returned ... I hope someone can help doing it is a simple way.

Regards,

Erik

Hi,

I'm trying to plot a function that contains an integral. I was finding that the plots seem to take far too long to make. When I just evaluate the function at a given point it computes almost instantly. So I tried setting setting adaptive plotting off and setting numpoints=5. This provides a plot very quickly (a few seconds) but if I raise the number of points up to 10 it runs indefinitely (I stopped it after 15 minutes). Could there be something else going on here? Does plot still evaluate at more than numpoints sometimes even if adaptive plotting is turned off?

Perhaps I am being blind, but I cannot locate a function for performing the direct sum of two (or more, for that matter) matrices, i.e., constructing a new matrix with the two (or more) matrices arranged block-diagonally.

Such a function should, I guess, naturally accompany the function KroneckerProduct in the LinearAlgebra package, because direct products (Kronecker products) of representations (i.e., matrrix-valued realizations of some abstract algebra) are, as is well-known, generally reducible into a direct sum of irreducible subrepresentations.